Pumps



www err- May 3, 1960 A. FERRARI, JR., ETAL 2,935,028

PUMPS Filed Aug. 5, 1957 4 Sheets-Sheet l ATTORNEYS May 3, 1960 A. FERRARI, JR., ET AL PUMPS 4 Sheer.s-Sheerl 2 Filed Aug. 5, 1957 May 3, 1960 PUMPS 4 Sheets-Sheet 5 Filed Aug. 5, 1957 FIG. 6A

INVENTORS Jac/f fsf?? 1 By Hnares fv/*arl 27? M VCI-A g-L ATTORNEYS May 3, 1960 A. FERRARI, JR., ET AL 2,935,028

PUMPS Filed Aug. 5, 1957 4 Sheets-Sheet 4 FIG. Il 7' T F B G. l 2 INVENToRs 194 ac sree/z' ATTORNEYS Puurs Andres Ferrari. .lr-.,Scarsdale and Jack lsreeli, Tuckahoe', N.Y., assignors, by mesne assignments, to Technicon Instruments Corporation, Chauncey, N.Y., a corporation of New York Application August 5, 1957, Serial No. 676,086 16 claims. (ci. 10s- 149) This invention relates generally to pumps of the exible tube type and, while of general utility, is especially applicable to proportioning pumps for pumping a plurality of fluids in predetermined relativevolumes.

One object of this invention is the provision of apump of the resiliently-exible tube type with resiliently acting means for accomplishing full closure of each of a plurality of tubes of different inner and outer diameters progressively along their lengths in the direction of fluid delivery, in the pumping operation, without interference with the complete closing of a tube of internal diameter by one or more tubes of other internal diameters.

Another object is the provision' of a multi-tube pump having resiliently-flexible tubes of different outer diameters and different inner diameters but in which all of said tubes can be simultaneously closed at points progressively along the lengths of the several tubes for the pumping operation, notwithstanding that the tubes have different inner diameters.

Another object is the provision of a pump of the designated type with means for preventing the formation of apermanent set in any of the tubes, whichI would impair their ability to elastically regain their full expanded con-V dition when relieved from tube closing pressure.` v

Another object in respect to one present embodiment of the invention is to provide a highly novel mounting for a platen on which the exible tubes are disposed so astol provide for a universal motion of the'platen for pressure equalization against tubes of diiferentouter diameters and yet to stabilize the platen against longitudinal and lateral motion thereof.

Another object is the provision of an improved mounting for the platen, on which the flexible tubes are disposed, so as to greatly increase the eiciency of the pump.

' Another object, in respect tolanother embodiment 'of Y the invention is to provide a pump in which tube closingA members are resiliently mounted individually in a 'rotary cylinder in circumferentially spaced relation.

A further object is the provision of a synchronous motor operated pump of the designated type with means toenable the motor to attain its synchronous speed before the iullV load is applied and to control the operation of the motor automatically by the relative position'of certain operative parts of the pump.

The above and other objects, features and advantages of this invention will be more fully understood fromv the following description considered in connection with the accompanying illustrative drawings.

In the drawings: p

Fig. l is a top plan view of a pump embodying the present invention;

l@ nited States Patent kFig. 2 is a sectional View, with parts in elevation, on the line`2 2 of Fig. 1;

Fig. 3 is anend view of the pump with parts broken away and other parts shown in section on the line 3 3 of Fig. 1, and showing the tube compressing mechanism partly displaced from its fully operative position;

Fig. 4 is a sectional view of part of the apparatus show-Y ing the tube fion;

u Fig. 5 is a detail sectional view on the line 5 5 of Fg- 4; t

Fig. 6 is a sectional view of parts of the apparatus, taken on the same line as Fig. 3 but showing the tube compressing mechanism in fully retracted position;

Figs. 6A and 6B are more or less diagrammatic views illustrating the provision of flexible tubes of different sizes, but of the same wall thickness, and showing the fully opened and fully closed conditions of said tubes;

Fig. 7 is a sectional view on a larger scale on theline 7 7 of Fig. 1 showing part of the tube compressing mechanism displaced from its operative position; v Pig. 8 is a detailed sectional view on the line 8 8 of FgJ;

Fig. 9 is a horizontal sectional view on the line 9 9 of Fig. 2; l

Fig. l0 is a sectional'view of another form of pump embodying the present invention;

Fig. 11 is a-sectional view on the line 11 11 of Fig. 10; andi- Fig. 12 is` a fragmentary view on a larger scale illustrating the bearing one end of the tube compressing roller.

Referring now to the drawings in detail and iirst to the form of the invention illustrated in Figs. 1 to 9, the pump 10 comprises a base 12 which is in the form of a housing for the electric motor M by which the pump is operated. A rigid platen 14 is resiliently mounted on base 12, and for that purpose is supported by springs '16 which surcompressingmechanism in operative posiround companion pins 18 which are connected tothe Fig. V6.

The above described Vspring mounting of the platen-14 on the base 12 provides for limited universal self-adjustment of the platen during the operation of the tubecompressing mechanism 26. The means providing for said self-adjustment of said platen includes the stabilizing means comprising a member 28 (Figs. 2 and 9) pivotally mounted on the base by means of a pivot pin 29 in a bearing block` 30 secured to the top of the base. Memberl 28 is also pivotally secured to a member 32 which is attached to the bottom of platen 14 by means of screws 34." The securement of member 32 to member 28 is such as to provide a universal joint between platen 14 and base 12. For this purpose the connection between members 28 and 32 includes apart 36 fixed to member 32 and pivotally mounted in member 28 by the pivot pin 38, and member 32 is mounted for movement around a pivot pin 40 which is held in relation to part 36 by said pin 38 which engage the pivot pin 40 in the reduced portion 41 thereof, Thus, member 32 Vcan pivot about two axes at right angles to each other, namely about thc axis of the pivot pin 38 and about the axis of pivot pin 40, providing, in effect, a universal joint for the platen in conjunction with the resilient mounting thereof.

The platen 14 acts in conjunction with the mechanism 26 to effect resiliently the closure of the tubes T of the pump for the pumping operation. See in this connection, Figs. 3, 4, 6A and 6B. The tubes T are held in engagement with the upper surface of the platen by the tube retaining and positioning members 42 which are removably mounted on the platen 14 adjacent the opposite ends thereof. For this purpose the platen is provided with upstanding pins 44 and members 42 are provided with a plurality of spaced openings 46 to provide for the adjustable mounting of the members 42V in longitudinally spaced relation on platen 14, it' being understood that pins 44 are receivable in a pair of laterally spaced openings 46. The members 42 have a plurality of longitudinally extending grooves 48 for holding the tubes T in laterally spaced relation. Said members 42 have lower recessed portions 49 in which collars 50 fixed, respectively, to the tubes T are engaged for holding the tubes in relation to the members 42. The tubesl T are formed of resiliently flexible material, for example a vinyl plastic, and they can be placed in taut condition without appreciable elongation or stretching. As the members 42 are easily placed in position on the platen and removable therefrom by engagement with and disengagement from the mounting pins 44, the tubes can be readily assembled with members 42 and mounted on the platen as a universal assembly and likewise they can be removed as a unit from the platen for replacement by another set of tubes.

The tube compressing mechanism 26 comprisesa frame plate '52 on which the endless sprocket chains 54 and 56 are mounted for movement. Said chains carry and thereby actuate a plurality of rollers 58 which are mounted by bearing pins 59 which are fixed in links 59 of the chains (Fig. 4), there being a bearing pin for each end of the roller, as will be readily understood. Sprocket chains 454 and 56 are driven by the sprocket wheels 60 and 62, respectively, fixed to a rotary shaft 64 journalled for rotation in an integral end extension 66 of plate 52. Said chains move over the side members 68 of plate 52 and run over the curved end portions 70 of said sides in anti-friction engagement therewith, thus making it possible to eliminate a pair of sprocket wheels.

Each side `68 of plate 52 is provided with a groove 72 in which a suitable solid lubricant may be disposed for contact with the links of the sprocket chains during the movement of the latter in relation to frame plate 52.

The tube compressing mechanism 26 is mounted for movement from the retracted position illustrated by Fig. Y'

6 to the operative position illustrated by Fig. 4, and through the intermediate position illustrated by Fig. 3. The means provided for this purpose comprises a mounting block 74 fixed to one of the sides 68 of said plate and pivotally mounted by a pivot pin 76 in a bracket 78 secured to the top of base 12. A releasable spring projected latch 80 (Figs. 4 and S) is provided for engagement with a handle and catch member 82 lfixed to plate 52, whereby to hold the mechanism 26 releasably in operative relation to the tubes 0n platen 14, during the operation of the pump. As illustrated, latch 80 `is pivotally mounted on a pivot pin 81 on a block 81a and is biased by a tension spring 83 to its projected position illustrated in Figs. 4 and 5. The upper end of latch 80 has a slanting cam face portion `84 which is engaged by catch member 82 when the latter is moved downwardly, so that latch 80 is moved automatically to a retracted position until catch 82 clears cam portion 84, after which latch 80 automatically moves under the force of spring 83 to its retaining position. A finger piece 85 is provided on said latch 80 for convenience in releasing it from catch 82 to enable the tube compressing mechanism 26 to be moved to its retracted position.

Provision is made for engaging and disengaging the sprocket chain driven shaft 64 from the actuating shaft 86 (Fig. 7) n such manner that the electric motor M, which is a synchronous motor in order to obtain a constant speed of travel of the pump compressing rollers 58, attains its synchronous speed before the motor is subjected to the full operating load. For this purpose, a releasable driving connection is provided between shafts 64 and 86. Such driving connection comprises a clutch member 88 fixed to the end of actuating shaft 86 and provided with a groove 89 and a companion clutch member 90 xed to shaft 64 and provided with a rib 91 engageable in groove 89 in interiitting relation therewith (Figs. 1, 7 and 8). Shaft 86 is biased for axial movement to a projected operative position by a compression spring 92, said shaft being slidably mounted in a bearing block 94. It will be understood that when the mechanism 26 is moved from the position illustrated by Fig. 6 to the position illustrated by Fig. 4 and through the intermediate position illustrated by Fig. 3 a driving engagement will be made between'shafts S6 and 64 by reason of the fact that shaft 86 is actuated before mechanism 26 is moved to its fully projected position so that when groove 89 is in alignment with rib 91, as illustrated in Fig. 7, spring 92 is effective to project clutch member 88 to the left, viewing Fig. 7, to provide the driving connection. It will be observed that shaft 86 is provided with a sprocket wheel 96 fixed thereto and driven by the sprocket chain 97 which is actuated by a sprocket wheel 98 driven through suitable reduction gearing by the motor M, and it will be readily understood that the sprocket chain 97 is sufiiciently flexible to permit the degree of longitudinal movement of shaft 86 needed for the engagement and disengagement of the clutch members 88 and 90.

In accordance with the present invention provision is made to operate the electric motor M under the control of the tube compressing mechanism 26 so that in order to stop the motor it is necessary to move the mechanism 26 to its retracted position. By thus requiring that the tube compressing mechanism 26 be moved to this retracted position in order to stop the actuating motor provision is automatically made for requiring disengagement of the tube compressing rollers from the tubes when the operation of the pump is discontinued. This is of considerable importance because prolonged compression of the tubes while the sprocket and while the roller operated chains 54 and 56 are stationary would result in the formation in said tubes of a permanent set as a result of which the elastic recovery quality of the tubes would be impaired and the pump would not operate properly. In this connection, it will be readily understood that during the travel of the rollersSS longitudinally of the tubes, compression of the tubes progressively along their lengths takes place for the pumping operation and that as the rollers progressively disengage the tubesY along their lengths, by reason of their inherent resiliency, regain their fully normal expanded condition, i.e., to the extent of their internal diameter in order to receive tlie proper quantity of fluid therein. In order thus to control the operation of the motor M in accordance with the position of the pump compressing mechanism 26 the switch actuating device 100 (Figs-3,- 4, and 6) is provided. Said device comprises the longitudinally movable pin 102 of a normally open microswitch 104. Fig. 4 shows the switch closed by the pressure exerted on pin 102, through closure cap 106, and it will be understood that when said pressure is relieving the resilient switch opening pressure of the switch will return pin 102 to its retracted position illustrated in Fig. 6 which also shows the switch in its open position. `The resilient cap 106 provides a uid seal at the top of the base so that liquids which might be spilled on top of ,the has@ are prevented from passing into theA housingthrough the opening for the switch actu-` ating pin 102." Also, as here shown, cap 106 provides means. for supporting the microswitch 104 and for that purpose said cap is provided with a metal nut 108 for engagement with the screw threaded nipple 110 fixed to the casing of the microswitch.

Thus, it will be noted that when the tube compressing mechanisml 26 is moved toward its operative position, and reaches the intermediate position illustrated in Fig. 3, it eirertsV a downward pressure on platen 14 and the latter presses against Ithe switch closing pin 102, through resilient cap 19t), for closing the switch and starting the opera- Vtionof motor M before the mechanism 26 is moved to its fully, operative position. This enables the synchronous motor M to reach full speed before being subjected to 'f ll' load. As previously explained, in the intermediate position of mechanism 26 illustrated by Fig. 3 the rotation `of actuating shaft 86, driven by motor M, results in the clutching of said shaft to the roller actuating shaft 64, so that the sprocket chains which carry said rollers are actuated and as the mechanism 26 is moved from its intermediate position to its fully projected position, the load is Hgradually applied to the motor.

"An important feature of the present invention is the provision for fullyclosing the tubes T progressively along their lengths by the rollers 58 even though the tubes T or some of them may be of different inner diameters. In this connection, it will be understood that the pump of the present invention is especially well adapted for use as a proportioning pump ,so that different quantities of liquid may be delivered in predetermined relative amounts, asmay be required in the various uses to which the pump can'be put. Thus, for example, as illustrated in Fig. 6A, certain of the tubes T have a larger internal diameter than Vothers of the tubes, and several of the tubes may have the sarneinternal diameter, but, as illustrated in Fig. 6B in the operation of the` pump all of the tubes, irrespective of ytheir internal diameters areV fully compressed and closed bythe roller which engages all of the tubes transversely thereof for the pumping operation. This important result is accomplished by providing tubes of the same Wall thickness irrespective of their internal diameters so that the tubes of larger diameter are fully closed when the tube or tubes4 of asmaller diameter or diameters are fully closed, and this result'is accomplished without the application of abnormal tube closing pressure to the tubes of the smallest internal diameter in the group of tubes onfplaten 14.

In theoperation ofthe pump, the endlessconveyor comprising the ychains 54 and 56 travels in the direction of the arrow A in Fig. 2 and moves rollers 5g along the lengths of the tubes for fully compressing the latter againstl the platen progressively from right to left, viewing Fig. 2. As shown in Fig. 2, there is a forward roller 58 and rear roller in the lower run of the chains, and the forward roller has advanced beyond the inclined portion 14a'which is provided in order that the fluid pressure in the tubes may be gradually decreased as the forward roller commences to disengage the tubes, thus avoiding an abrupt decrease in pressure which might otherwise occur. It will be understood that the rear roller 58,611- gages the Vtubes before they are disengaged by the forward roller, so that back flow of fluid in the tubes is prevented.

Referring now to the form of the invention illustrated by Figs. to 12, the rollers 58' for compressing the tubes T progressively along their lengths, for the pumping operation, as described above are carried by a cylindrical carrier 111 which is rotated by a rotary shaft 112 mounted in the stationary frame 114. Shaft 112 can be rotated in any suitable way as by the gear 116 which is Xed to the shaft and which is rotated by a toothed flexible belt 118 operated by a synchronous electric motor (not shown). Each of the several rollers 58' is resiliently mounted at its opposite ends in radiallyslidable 6 s leeves 120- which a-reurged radially outwardly by com, pression springs 122. One of said sleeves is shown in elevation in Fig. 10, a part ofcylinder 111 being removed for the purpose of this illustration, and it will be observed by reference to Figs. l0 and 1l that said sleeves are each guided for movement in a cylindrical radial opening 124 in the side plates 126 which are removably secured in any suitable way as by the screws 128 to the opposite ends of rotary cylinder 111 and form parts of said cylinder for rotation therewith. The. inner ends of spring 122 abut iiats on the shaft 112 and sulicientspace is provided betweeny the inner end of each cylinder 120 and the shaft to permit movement of spring biased cylinders 120 inwardly and thereby permit movement of the rollers 58 inwardly when the platen 130 isi in operative position f orv conipression ofl the tubes T in the pump operation. It will be observed that rollers 58' have short end portions 132 which pass through openings 136 suliiciently large to en-l able the roller to tilt or` cant, if necessary, in orderto compensatel for any inequalities. Circular spring rings V1398 are provided on carrier 111 peripherally thereof for limitingthe outward movement of cylinders 120 under the pressure of their companion springs.

The platen 130 is mounted for pivotal movement by means of a pivot pin 140 carried by the frame members 115 and is held in operative position, as illustrated by Fig. l1, by the releasable pin 142 which is movable through an opening 144 in the catch 146 carried by the platen and an opening 148 in the other frame member 114.

As in thecase of platen 14 in Figs. 1 to 9, the platen 130 has a pressure-relieving portion, indicated at 141 so that as the forward pressure roller is about to disengage the tubes T, carrier 111 rotating counterclockwise, the fluid pressure in tubes T is gradually decreased.

Aimicro-switch 104' is supported by the frame member 114 adjacent the pivoted end of platen 130 in position to have its operating pin 162' engaged by an end portion of saidplaten as illustrated in Fig.- 11 so that the switch is closed when the platen is in its operative position and is opened when the platen is moved to a retracted position for starting and stopping the operating motor, for the same purpose as in the case of the pump described above with reference to the formof the invention illustrated by Figs. 1 to 9.

Also, it will bet'understood that before the platen is movedto its fully projected position, illustrated in Fig. 11, there is an intermediate position at which switch 104v is closed by the engagement of the platen with pin 102, so that thesynchronous motor for rotating shaft 112 can be brought upto synchronous speed before the platen is fully closed against the tubes T.

g It will be observed that inboth forms of the invention there are resilient acting means for simultaneously compressing all of the tubes progressively along their lengths for the pumping operation. In the first described form of the invention, the resilient action is obtained. by mounting the platen 14 on the springs 16, while in the form of the invention illustrated by Figs. l0 to 12 the resilient action is obtained by mounting the rollers 58 on the 'spring biased cylinder bearing members 120. In both cases, however., the-resilient acting means comprises a platen and a plurality of rollers. Also, in both forms of the invention the tubesY T which may have diiferent linternal diameters have the same wall thickness so that they are fully closed by the same roller during the operation of the pump. It will be noted also that in both forms of the invention the switch which controls the operation of the motor, is operated to stop the motor insuch a way that the pressure on the tubes is relieved automatically when the motor is stopped so that the formation of a permanent set in the tubes which might occur if the pressure is not relieved whenthe pump is stopped is prevented.

The subject matter of this application isV related to our U.S. applications, Ser. No. 463.860.v led .October..22j.

1954, new Patent No, 2,865,303 and Ser. No. 628,030, filed December 13, 1956, now Patent No. 2,893,324 both assigned to the assignee of this application. As stated in said earlier application, the pump of the present invention is particularly well adapted for use in lthe liquid analysis apparatus disclosed in the application to Leonard T. Skeggs, now United States Patent No. 2,797,149 owned by the assignee of this application. It will be understood, however, that the pump of the present invention may be used for various other purposes, especially as a proportioning pump.

Thus it is seen that the pump embodying the present invention is well adapted to accomplish the several objects thereof in both forms or embodiments of the invention described above. It will be undestood, however, that the invention may be embodied otherwise than as hereinbefore shown or described and that in the illustrated and described embodiments certain changes in the details of construction and in the arrangement of parts may be made and will occur to persons skilled in this art, in view of the present disclosure, without departing from the underlying idea or principles of this invention. Accordingly, we do not wish to be limited to the precise constructions herein shown or described except to the extent which may he required by the scope of the appended claims considered with reference to the prior art.

Having thus described our invention, what we claim and desire to secure by Letters Patent is:

1. In a tluid pump of the class described, a plurality of tubes disposed laterally of each other for the delivery of a plurality of uids in different predetermined relative amounts, said tubes being resiliently ilexible and of diff ferent internal diameters but all having substantially the same wall thickness so that all of said tubes can be closed simultaneously at points intermediate their lengths, respectively, along a common transverse line, by equal compression of the tubes -at said points, respectively, whereby the full closing compression of a tube of a smaller internal diameter does not interfere with the full closing compression of a tube of a larger diameter and a pressure roller simultaneously engageable with all of said tubes along a common transverse line and movable progressively along the lengths of said tubes for fully compressing them progressively along their lengths.

2. In a uid pump of the class described, a plurality of tubes disposed laterally of each other for the delivery of a plurality of uids in different predetermined relative amounts, said tubes being resiliently exible and of diierent Vinternal diameters but all having substantially the same wall thickness so that all of said tubes can be closed simultaneously at points intermediate their lengths, respectively, along a common transverse line, by equal compression of the tubes at said points, respectively, whereby the full closing compression of a tube of a smaller internal diameter does not interfere with the full closing compression of a tube of a larger diameter, and resilient acting means associated with said tubes for simultaneously compressing all of said tubes progressively along their lengths for the pumping operation, said resilient acting means engaging all of said tubes simultaneously along said common transverse line.

3. In a fluid pump of the class described, a plurality of tubes disposed laterally of each other for the delivery of a plurality of iiuids in diterent predetermined relative amounts, said tubes being resiliently exible and of dierent internal diameters but all having substantially the same wall thickness so that all of said tubes can be closed simultaneously at points intermediate their lengths, respectively, along a common transverse line, by equal compression of the tubes at said points, respectively, whereby the full closing compression of a tube of a smaller internal diameter does not interfere with the full closing compression of a tube of a larger diameter, and resilient acting means for simultaneously compressing all of said tubes progressively along their lengths for vthe pumping operation, said resilient acting means comprising a platen and a plurality of rollers engageable with said tubes transversely thereof at lines spaced from each other longitudinally of said tubes and each extending transversely of all of said tubes for fully compressing all of said tubes simultaneously against said platen.

4. In a fluid pump of the class described, a plurality of tubes of dilerent internal diameters disposed laterally of each other for the delivery ofv a plurality of tiuids in diterent predetermined relative amounts, said tubes being resiliently liexible, a plurality of spring pressed rollers engageable with said tubes for simultaneously compressing all of said tubes progressively along their lengths for the pumping operation, and a platen movable from a retracted position to a projected position against said tubes for said compression of the tubes thereagainst by said spring pressed rollers.

5. In a uid pump of the class described, a plurality of tubes of different internal diameters disposed laterally of each other for the delivery of a plurality of fluids in different predetermined relative amounts, said tubes being resiliently flexible, a plurality of spring pressed rollers engageable with said tubes for simultaneously compressing all of said tubes progressively along their lengths for the pumping operation, a rotary carrier on which said rollers are mounted in circumferentially spaced relation, and a platen movable from a retracted position to a projected position against said tubes for said compression of the tubes thereagainst by said spring pressed rollers.

6. In a fluid pump of the class described, a plurality of tubes disposed laterally of each other for the delivery of a plurality of iluids in different predetermined relative amounts, said tubes being resiliently flexible and of different internal diameters but all having substantially the sarne wall thickness so that all of said tubes can be closed simultaneously at points intermediate their lengths, respectively, along a common transverse line, by equal compression of the tubes at said points, respectively, whereby the full closing compression of a tube of a smaller internal diameter does not interfere with the full closing compression of a tube of a larger diameter, a plurality of spring pressed rollers engageable with said tubes progressively along their lengths for the pumping operation, and a platen movable from a retracted position to a projected position against said tubes for said compression of the tubes thereagainst by said spring pressed rollers.

7. In a tiuid pump of the class described, a plurality of tubes of difrerent internal diameters disposed laterally of each other for the delivery of a plurality of fluids in diierent predetermined relative amounts, all of said tubes having the same wall thickness, said tubes being resiliently iiexible, means including a platen and a plurality of rollers engageable with said tubes for simultaneously compressing them and completely closing all of them progressively along their lengths simultaneously for the pumping operation, and a rotary carrier on which said rollers are mounted for said compressing engagement with the tubes, and spring means on said carrier operatively connected to said rollers for pressing them resiliently against the tubes for compressing them resiliently against said platen.

8. In a uid pump of the class described, a plurality of tubes of different internal diameters disposed laterally of each other for the delivery of a plurality of uids in diierent predetermined relative amounts, all of said tubes having the same wall thickness, said tubes being resiliently exible, means including a platen and a plurality of rollers each releasably engageable with a plurality of said tubes for simultaneously compressing them and completely closing all of them progressively along their lengths simultaneously for the pumping operation, and a rotary carrier on which said rollers are mounted for said compressing engagement with the tubes, and spring means on said carrier operatively connected to said rollers for pressing them resiliently against the tubes for compressing them i9 resiliently against said, platen said'platen having aconcave surface against which said tubes are pressed; bysaid rollers. Y.

9. In a uidpump of the class described, a'pluralityof tubes disposed, laterally of each other for the delivery of a plurality of fluids in different predetermined relative amounts, said tubes being resiliently llexible and of different internal `diameters ,but all `having substantially `the same wall thicknesslsothat all of Ysaid tubes can be closed simultaneously at points intermediate their lengths, respectively, along a common transverse line, by equal compression of the tubes at said points, respectively, whereby the full closing compression of a tube of a smaller internal diameter does not interfere with the full closing compression of a tube of a larger diameter, and resilient acting means for simultaneously compressing all of said tubes progressively along their lengths along said common transverse line for the pumping operation, said resilient acting means comprising a platen and a plurality of rollers engageable with said tubes transversely thereof at lines spaced from each other longitudinally of said tubes and each extending transversely of all of said tubes, there being forward and rear rollers, respectively, each of said rollers extending transversely of said tubes along said common transverse line and spaced from each other longitudinally of said tubes and engageable with and disengageable from said tubes, the rear one of said rollers being operable to simultaneously engage and compress all of said tubes to completely close the passages therethrough `at the time of disengagement of the forward roller from said tubes.

10. A uid pump comprising a backing member for supporting a plurality of exible tubes having different outer diameters in side-by-side relation, means operable to compress said tubes progressively along their lengths for forcing the fluid therethrough, and means mounting said backing member. for universal motion so as to equalize the pressure applied against said tubes of diierent outer diameters by said compressing means, said mounting means including springs arranged to support said backing member at longitudinally spaced points thereof and at laterally spaced points thereof, and means pvotally mounting said compressing means for movement to and from an operative position in relation to said backing member for moving the latter against the pressure of said springs and thereby applying resilient pressure on 'the tubes on said backing member, for the pumping operation.

ll. In a fluid pump of the class described, a plurality of tubes of dilerent internal diameters disposed laterally of each other for the delivery of a plurality of liuids in different predetermined relative amounts, said tubes being resiliently exible, means including a platen and a plurality of rollers engageable with said tubes for simultaneously compressing them progressively along their lengths for the pumping operation, and a rotary carrier on which said rollers are mounted for said compressing engagement with the tubes, and spring means on said carrier operatively connected to said rollers for pressing them resiliently against the tubes for compressing them resiliently. against said platen, and means mounting said platen for pivotal movement from an operative position above said carrier to a retracted position clear of said carrier when the tubes are to be positioned in relation to said rollers or removed therefrom.

12. In a uid pump comprising a frame, means mounted on said frame for supporting a plurality of flexible tubes in side-by-side relation, la plurality of resiliently exible tubes disposed in said side-by-side relation on said' frame, and means operable for compressing said tubes for the pumping operation, said mounting means comprising members positioned on said frame in spaced relation longitudinally of said tubes, said members having means for holding said tubes in laterally spaced relation on said frame, said tubes having external enlargements xed thereto, respectively, at both their inlet and outlet ends and said holding members having abutments engageabli by said enlargements of said tubes to prevent-longitudinal movement of said tubes on said frame in either direction longitudinally of the tubes.

13. In a uid pump comprising a frame, means mount ed on said `frame for supporting a plurality of exible tubes in side-by-side relation, a plurality of resiliently flexible tubes disposed-in said side-by-side relation on said frame, and means operable for compressing said tubes for thepumping operation, said mounting means comprising members positioned on said frame in spaced relation longitudinally of said tubes, said members having open-top grooves in which said tubes are positioned, respectively, and thereby held in laterally spaced relation on said frame, and interengaging means on saidvframe and on said members for releasably and adjustably holding said members on said frame.

14. In a uid pump comprising a frame, means mounted on said frame for supporting a plurality of flexible tubes in side-by-side relation, a plurality of resiliently ilexible tubes disposed in said side-by-side relation on said frame, and means operable for compressing said tubes for the pumping operation, said mounting means comprising members positioned on said frame in spaced relation longitudinally of said tubes, said members having opentop grooves in which said tubes are positioned, respectively, and thereby held in laterally spaced relation on said frame, and interengaging means` on said frame and on said members for releasably and adjustably holding said members on said frame, said tubes having external enlargements and said holding members having abutments engageable by said enlargements of said tubes to prevent longitudinal movement of said tubes on said frame.

15. In a fluid pump which comprises a platen, a plurality of resiliently ilexible tubes mounted in side-by-side relation, roller means operable in conjunction with said platen and movable progressively along the length of said tubes for fully compressing themagainst said platen progressively along the lengths of the tubes simultaneously along a common transverse line, a frame on which said roller means are mounted said frame being movable from a retracted position to a projected position for moving the roller means into and out of operative engagement with said tubes, a motor for actuating said roller means, and a releasable driving connection between said motor and said roller means comprising a driving rotary clutch member actuated by said motor and a driven rotary clutch member mounted on said frame operatively connected to said roller means, said driven clutch member being automatically engaged with said driving clutch member when said frame is moved for moving said rollers into operative engagement and being automatically disengaged from said driving clutch member when said frame is moved to said retracted position.

16. In a iiuid pump which comprises a platen, a plurality of resiliently exible tubes mounted in side-by-side relation, roller means operable in conjunction with said platen and movable progressively along the length of said tubes for fully compressing them against said platen progressively along the lengths of the tubes simultaneously along a common transverse line, a frameon which said roller means are mounted said frame being movable from a retracted position to a projected position for moving the roller means into and out of operative engagement with said tubes, a motor for actuating said roller means, and a releasable driving connection between said motor and said roller means comprising a driving rotary clutch member actuated by said motor and a driven rotary clutch member mounted on said frame operatively connected to e said roller means, said driven clutch member being automatically engaged with said driving clutch member when said frame is moved for moving said rollers into operative engagement and being automatically disengaged from said driving clutch member when said frame is moved to said retracted'position, and switch means operable under References Cited in the le of this patent UNITED STATES PATENTS MOI'OD Jan. 30, 1883 Dieckmann Oct. 25, 1898 10 12 Y f Santiago Jan. 15, 1935 Knott Mar. 16, 1943 Jones Nov. 9, 1943 Stocks ...L Apr. 5, 1949 Corneil Mar. 27, 1951 FOREIGN PATENTS Great Britain June 15, 1937 Great Britain Feb. 8, 1956 

